Php undefined index error

Question

1.00/5 (1 vote)

See more:

PHP

<?php 
   if ($_SESSION['C'] == false) 
   {
    echo "<a href='admin/' class='logo1' title='Login' ><img src='image/login.png'>
   <span>Login</span></a>";
}

Notice: Undefined index: C in C:\xampp\htdocs\Souvenir_Mysql\souvenir_bkt\index.php on line 3913

PHP

<?php 
  if ($_SESSION['C'] == true) {
    echo $_SESSION['username']; 
  }

Notice: Undefined index: C in C:\xampp\htdocs\Souvenir_Mysql\souvenir_bkt\index.php on line 3997
Visitor !

What I have tried:

I have the new version of mysql
I thought it was because of it

Posted 14-Sep-20 2:49am

Member 14928540

Updated 14-Sep-20 22:46pm

Richard Deeming

v2

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sandeep Mewara · Answer 1 · 2020-09-14T03:28:00

Quote:

This error means that within your code, there is a variable or constant that has no value assigned to it. But you may be trying to use the values obtained through the user form in your PHP code.

The error can be avoided by using the isset() function. This function will check whether the index variables are assigned a value or not, before using them.

Based on the error and code lines you share, it seems the $_SESSION['C'] is not defined. i.e.: Index 'C' does not exists in the variable $_SESSION.

You have the entire code. Use DEBUGGER and step through to see the same and then find why so, handle it. If isset() helps, go ahead and use it based on the flow.

Refer:
PHP isset() Function[^]
PHP: Debugging in PHP - Manual[^]